1. Field of the Invention
The present invention relates to an oil field apparatus or tool, and more particularly relates to an improved power tong. Even more particularly, the present invention related to an improved power tong providing jaw assemblies which are rotationally mounted within the respective jaw carriages and are powered by hydraulic cylinders. Even more particularly, extending jaw chambers are provided which allow the hydraulic cylinders to be moved between left and right positions which combined with an inverting of the respective jaw assembly different rotational directions to each jaw assembly.
2. General Background and Prior Art
In the oil field and in oil/gas drilling, there is often utilized a "power tong" for making up and breaking up sections of drill pipe, casing, or other like piping assemblies which are generally made up into strings from a plurality of joints. Many of these power tongs are in use which quickly make or break the desired connection using power supplied by an electric or hydraulic motor, for example. In general, power tongs of this type have clutch, drag or brake assembly which transforms rotary power through a gear reduction system into gripping power through a cam mechanism, thus allowing the pipe to be gripped at the joint and the desired torque applied. Power tongs of this type are known.
In U.S. Pat. No. 2,862,690 issued to James C. Masou, which provides for a power driven device for rotating piping or casing utilizing a series of endless belt in the rotating of the pipes.
In U.S. Pat. No. 3,793,913 issued to Carl A. Wilms, there is provided a power tong for making up and breaking up pipe adapted with a reverse stop means.
In U.S. Pat. No. 3,144,794 issued to J. L. Foster entitled "Power Driven Sucker Rod Wrench," relates to a power actuated sucker rod tong or wrench, and more particularly to a wrench mechanism for connecting and disconnecting the screw threaded joints of pump rods.
U.S. Pat. No. 4,084,453 issued to E. L. Eckel, entitled "Power Tong" includes a power tong which has a frame and pipe gripping mechanism associated with a throat at one end of the frame wherein power is transmitted to the pipe gripping mechanism from a power unit through a drive train.
U.S. Pat. No. 2,509,853 issued to N. K. Wilson entitled "Tubing and Rod Handling Tool," wherein a tool is provided with a frame having a roller means adapting the frame to roll up on a track having clamp means at one end for connection upon a well casing thereto.
U.S. Pat. No. 3,541,897 issued to H. D. Horton entitled "Power Tubing Tongs," wherein is included an external housing having a bull gear assembly disposed for the major circumferential difference thereby with the external housing being adapted to receive a removable internal jaw section therein.
U.S. Pat. No. 3,892,148 issued to Mark H. Wiley, entitled "Adjustable Power Spinning Tongs" provides an apparatus which involves a power spinning tong of the type having rollers which grip the pipe and some of its rollers are rotatable to drive the pipe rotatively, the rollers being revolvable on lever arms that can be opened to allow the tong to be applied to and removed from the pipe.
U.S. Pat. No. 4,005,621 issued to J. W. Turner, Jr. and Russell A. McLaughlin entitled "Drilling Tong," which utilizes an open head tong of the type utilized to handle large diameter work pieces, such as drill pipe and casing for oil field application and including means to adjustably engage peripheral portions of such work pieces.
U.S. Pat. No. 4,060,014 issued to John W. Turner, Jr. entitled "Power Tong" provides for an open head power tong for use in making up and breaking up joints of varying diameter such as drill pipe joints which provides for bidirectional operation with the tong housing remaining in the same position.
U.S. Pat. No. 3,021,739 issued to J. F. Grundmann entitled "Hydraulically Controled and Operated Power Tong," which includes a rotatably mounted head portion having an opening in which a cylindrical member may be positioned coincident with the axis of rotation of the head portion and there is a power means operable to rotate said head portion, said gripping members being actuatable into gripping engagement and out of gripping engagment.
U.S. Pat. No. 2,741,460 issued to R. I. Gardner entitled "Power Tongs and Control System Therefor," which provides for a power wrench including a housing which provides an annular stator, an annular rotor carrying a suitable pipe gripping structure being disposed within the annular stator and being rotatable about the axis thereof.
U.S. Pat. No. 2,703,221 issued to R. I. Gardner entitled "Power Tong," which is essentially the same apparatus as the previous patent to the same inventor.
Most prior art devices as is evidenced from the prior arts patents cited are extremely complex in construction and are difficult and/or impossible to replace in the field should the need arise. Further, they are generally constructed so that there are numerous moving parts and are drive train apparatus, gears, etc. which the use of oil field work require immediate attention should a breakdown occur which indeed does happen very often.
3. General Description of the Present Invention
The present invention provides an improved power tong apparatus which would comprise a housing having a U-shaped vertical slot with a vertical axis which would normally be occupied by a pair of pipe lengths to be assembled or disassembled as in oil field work. The apparatus would also have a pair of jaw assemblies which would be movably mounted on a housing and adapted with a pair of oppositely oriented hydraulic cylinders which would be connected respectively to the pair of jaw assemblies and produce opposite rotational motion of each. Each jaw assembly would be powered during the operation by one of said cylinders to a first pipe gripping position and thereafter to a second pipe rotating position. In the embodiment, the pair of jaw assemblies would be cylindrical and are mounted within the cylindrical recesses provided respectively in the upper and lower portions of the housing. A pair of upper laterally extending chambers and a pair of lower laterally extending chambers would further comprise the housing.
Therefore, it is an object of the present invention to provide an improved power tong apparatus which is adapted for receiving pipe lengths for assembling and disassembling.
It is further an object of the present invention to provide a power tong which would be adapted with oppositely oriented hydraulic cylinders being connected to a pair of jaw assemblies and producing opposite rotational motion of each, therefore enabling assemblage and disassemblage of pipe lengths.
It is a further object of the present invention to provide a power tong where the pair of jaw assemblies are cylindrical and mounted within cylindrical recesses respectively in the upper and lower portions of the housing.
It is another object of the present invention to provide a power tong which is of simplified construction for hydraulically driven jaws for assembling and disassembling sections of pipe in the oil field industry.